TFF Optimization with Single-Use Systems

Tangential flow filtration (TFF) is an efficient separation technology that is widely used in the downstream purification of solutions containing molecules such as recombinant proteins (including mAbs), vaccines, or cellular debris. TFF has three primary applications in bioprocessing: clarification by microfiltration, concentration by ultrafiltration, and purification by diafiltration.

Important success criteria for all TFF processes are high product yield, high product quality, and high product purity. These success criteria are achieved, not just by the selection of appropriate filtration devices and operating parameters, but also by the implementation of well-designed process hardware.

Although the product processing time of a TFF step in a typical monoclonal antibody manufacturing operation is not excessive, the additional time required for installation, set-up, flushing, and cleaning of the TFF system and devices make it an ideal step to introduce disposable technology as a means of decreasing overall downstream processing time.

The introduction of single-use flowpath assemblies integrated with TFF membranes provides the opportunity to minimize set-up and cleaning time, decrease chances of cross-contamination from run to run, and capitalize on the opportunity for more flexible and rapid facility startup and change over.

The time and cost advantages of single-use systems over stainless-steel systems are well-documented; however, questions remain as to how the single-use system performs compared to historical processes. This study presents data demonstrating that a pre-engineered system for TFF utilizing completely single-use flowpaths can deliver optimal process performance in terms of yield, quality, and product purity through implementation of low working volume, excellent product recovery, effective mixing, and efficient removal of small molecules.

Mobius® FlexReady Solution for TFF

Millipore’s Mobius FlexReady Solution for TFF combines a process-ready hardware system with Flexware™ single-use assemblies designed for minimal working volume and high recovery of protein at high concentrations. The system is available with either a 10 L retentate recycle container utilizing Pellicon® cassettes of up to 0.5 m2 filtration area (TF-1), or a 50 L retentate recycle container using Pellicon cassettes of up to 2.5 m2 filtration area (TF-2). Pellicon cassettes were selected for their proven accuracy in scale-up and scale-down processes.

For both TF-1 and TF-2, the piping and instrument diagrams of the Flexware assemblies match the flowpaths of traditional stainless steel systems, with tubing diameters and materials of construction selected to enable the required flowrates and pressures of specific applications (Figure 1). The hardware and flowpaths were designed together to optimize layout and minimize excess tubing and connections. For this study, the TF-2 system was characterized over a range of process conditions.